URLto work with. The parameter should be a string which must be URL-encoded in the following format:
For a greater explanation of the format please see RFC3986.
libcurl doesn't validate the syntax or use this variable until the transfer is
issued. Even if you set a crazy value here, easy:SetOpt() will
If the given URL is missing a scheme name (such as "http://" or "ftp://" etc)
then libcurl will make a guess based on the host. If the outermost sub-domain
name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP then that protocol will be
used, otherwise HTTP will be used. Since 7.45.0 guessing can be disabled by
setting a default protocol, see
#CURLOPT_DEFAULT_PROTOCOL for details.
Should the protocol, either that specified by the scheme or deduced by libcurl
from the host name, not be supported by libcurl then
#CURLE_UNSUPPORTED_PROTOCOL will be returned from either the
easy:Perform() or multi:Perform() functions when you
call them. Use
curl_version_info for detailed information of which
protocols are supported by the build of libcurl you are using.
#CURLOPT_PROTOCOLS can be used to limit what protocols libcurl will
use for this transfer, independent of what libcurl has been compiled to
support. That may be useful if you accept the URL from an external source and
want to limit the accessibility.
#CURLOPT_URL string will be ignored if
#CURLOPT_CURLU must be set before a
transfer is started.
The host part of the URL contains the address of the server that you want to connect to. This can be the fully qualified domain name of the server, the local network name of the machine on your network or the IP address of the server or machine represented by either an IPv4 or IPv6 address. For example:
http://www.example.com/ http://hostname/ http://192.168.0.1/ http://[2001:1890:1112:1::20]/
It is also possible to specify the user name, password and any supported login options as part of the host, for the following protocols, when connecting to servers that require authentication:
http://user:email@example.com ftp://user:firstname.lastname@example.org smb://domain%2fuser:email@example.com imap://user:password;firstname.lastname@example.org pop3://user:password;email@example.com smtp://user:password;firstname.lastname@example.org
At present only IMAP, POP3 and SMTP support login options as part of the host. For more information about the login options in URL syntax please see RFC2384, RFC5092 and IETF draft draft-earhart-url-smtp-00.txt (Added in 7.31.0).
The port is optional and when not specified libcurl will use the default port based on the determined or specified protocol: 80 for HTTP, 21 for FTP and 25 for SMTP, etc. The following examples show how to specify the port:
http://www.example.com:8080/ - This will connect to a web server using port 8080 rather than 80.
smtp://mail.example.com:587/ - This will connect to a SMTP server on the alternative mail port.
The path part of the URL is protocol specific and whilst some examples are given below this list is not conclusive:
http://www.example.com - This gets the main page from the web server.
http://www.example.com/index.html - This returns the main page by explicitly requesting it.
http://www.example.com/contactus/ - This returns the default document from the contactus directory.
ftp://ftp.example.com - This retrieves the directory listing for the root directory.
ftp://ftp.example.com/readme.txt - This downloads the file readme.txt from the root directory.
ftp://ftp.example.com/libcurl/readme.txt - This downloads readme.txt from the libcurl directory.
ftp://user:email@example.com/readme.txt - This retrieves the readme.txt file from the user's home directory. When a username and password is specified, everything that is specified in the path part is relative to the user's home directory. To retrieve files from the root directory or a directory underneath the root directory then the absolute path must be specified by prepending an additional forward slash to the beginning of the path.
ftp://user:firstname.lastname@example.org//readme.txt - This retrieves the readme.txt from the root directory when logging in as a specified user.
smtp://mail.example.com - This connects to the mail server at example.com and sends your local computer's host name in the HELO / EHLO command.
smtp://mail.example.com/client.example.com - This will send client.example.com in the HELO / EHLO command to the mail server at example.com.
pop3://user:email@example.com - This lists the available messages for the user
pop3://user:firstname.lastname@example.org/1 - This retrieves the first message for the user
imap://user:email@example.com - Performs a top level folder list
imap://user:firstname.lastname@example.org/INBOX - Performs a folder list on the user's inbox
imap://user:email@example.com/INBOX/;UID=1 - Selects the user's inbox and fetches message with uid = 1
imap://user:firstname.lastname@example.org/INBOX/;MAILINDEX=1 - Selects the user's inbox and fetches the first message in the mail box
imap://user:email@example.com/INBOX;UIDVALIDITY=50/;UID=2 - Selects the user's inbox, checks the UIDVALIDITY of the mailbox is 50 and fetches message 2 if it is
imap://user:firstname.lastname@example.org/INBOX/;UID=3/;SECTION=TEXT - Selects the user's inbox and fetches the text portion of message 3
imap://user:email@example.com/INBOX/;UID=4/;PARTIAL=0.1024 - Selects the user's inbox and fetches the first 1024 octets of message 4
imap://user:firstname.lastname@example.org/INBOX?NEW - Selects the user's inbox and checks for NEW messages
imap://user:email@example.com/INBOX?SUBJECT%20shadows - Selects the user's inbox and searches for messages containing "shadows" in the subject line
For more information about the individual components of an IMAP URL please see RFC5092.
scp://firstname.lastname@example.org/etc/issue - This specifies the file /etc/issue
scp://example.com/~/my-file - This specifies the file my-file in the user's home directory on the server
sftp://user:email@example.com/etc/issue - This specifies the file /etc/issue
sftp://firstname.lastname@example.org/~/my-file - This specifies the file my-file in the user's home directory
sftp://ssh.example.com/~/Documents/ - This requests a directory listing of the Documents directory under the user's home directory
#CURLOPT_USERNAMEoption. If the user name is embedded in the URL then it must contain the domain name and as such, the backslash must be URL encoded as %2f.
smb://server.example.com/files/issue - This specifies the file "issue" located in the root of the "files" share
smb://server.example.com/files/ -T issue - This specifies the file "issue" will be uploaded to the root of the "files" share.
ldap://ldap.example.com/o=My%20Organisation - This will perform a LDAP search with the DN as My Organisation.
ldap://ldap.example.com/o=My%20Organisation?postalAddress - This will perform the same search but will only return postalAddress attributes.
ldap://ldap.example.com/?rootDomainNamingContext - This specifies an empty DN and requests information about the rootDomainNamingContext attribute for an Active Directory server.
For more information about the individual components of a LDAP URL please see RFC4516.
While space is not typically a "legal" letter, libcurl accepts them. When a user wants to pass in a '#' (hash) character it will be treated as a fragment and get cut off by libcurl if provided literally. You will instead have to escape it by providing it as backslash and its ASCII value in hexadecimal: "\23".